Street sweepers have long been known that include rotating brooms which sweep pavement or other surfaces to remove debris and clean the surface. Such brooms are typically mounted upon a horizontal axis oriented perpendicular to a direction of vehicle motion. The broom has bristles which impact the surface of the pavement. Many modern street sweepers not only sweep debris with the broom, but also have on-board storage adjacent the broom where debris swept by the broom can be picked up and removed for disposal.
In one common configuration, the broom is at the rear of the vehicle and directly forward of the broom is a bin into which debris is swept by the broom. For the broom to effectively sweep debris into the bin, the bin and broom must be precisely aligned with each other. To maintain this alignment, the street sweepers typically include skid plates on each lateral side of the broom which maintain broom alignment with other portions of the sweeper. Such skid plates have a drag shoe which is formed from hardened materials which allow the drag shoe to drag on the surface of the pavement being swept by the broom. The skid plates are mounted between two vertical rails of a track which allow the skid plate to move up and down, but prevent the skid plate from forward or rearward motion. The skid plates also keep debris from being deflected laterally away from the broom after being impacted by the broom and act to guide debris into the bin of the sweeper for removal.
Because the skid plate drags upon the surface being swept, the skid plate typically encounters a variety of extreme lateral forces from impacting objects such as curbs, speed bumps, pot holes, manholes, rail roads and other objects. Prior art street sweepers securely attach the skid plates to the sweeper in a manner only allowing the skid plate to translate vertically up and down, but do not allow the skid plate to have any other motion relative to the sweeper. Hence, when the skid plate impacts objects while the sweeper is moving over the surface being swept, unless the objects can be deformed by the skid plate or cause only vertical forces to be applied to the skid plate, the skid plate must be deformed. If the deformation which the object causes the skid plate to encounter exceeds the elastic limit of the skid plate, the skid plate will be permanently deformed to some extent and the sweeper will no longer function according to its design.
Accordingly, a need exists for an alternative configuration for attachment of the skid plate to other portions of the sweeper. Such a configuration would allow the skid plate to be deflected away from other portions of the sweeper somewhat when objects are impacted by the skid plate, but cause the skid plate to return to its original position after forces encountered by impacting the object have ceased.